Closely-spaced isobars on a map indicate:

All the following are things that cause climate changes from natural events, except:

When it is March and spring in the Northern Hemisphere, it is __________ and ___________ in the Southern Hemisphere.

What force causes surface winds to blow across isobars, unlike at upper levels?

A pressure gradient is which of the following?

The following are all types of air masses except:

The Earth is closest to the Sun in:

The primary force that initially causes air to move horizontally is the:

What type of air mass would be responsible for hot, humid summer weather in the eastern half of the United States?

During dehydration the body would increase production of